Estimates of the global potential of floating solar energy, based on available man-made water surfaces, is more than 400 GWp.
Like most planets in our solar system, the Earth has its own magnetic field. Thanks to its largely molten iron core, our planet is in fact a bit like a bar magnet. It has a north and south magnetic pole, separate from the geographic poles, with a field connecting the two. This field protects our planet from radiation and is responsible for creating the northern and southern lights – spectacular events that are only visible near the magnetic poles.
In 1960, famed theoretical physicist Freeman Dyson made a radical proposal. In a paper titled “Search for Artificial Stellar Sources of Infrared Radiation” he suggested that advanced extra-terrestrial intelligences (ETIs) could be found by looking for signs of artificial structures so large, they encompassed entire star systems (aka. megastructures). Since then, many scientists have come up with their own ideas for possible megastructures.
We tend to think of the moon as the archetypal “dead” world. Not only is there no life, almost all its volcanic activity died out billions of years ago. Even the youngest lunar lava is old enough to have become scarred by numerous impact craters that have been collected over the aeons as cosmic debris crashed into the ground.
On the one hand, cheese is an excellent source of minerals like calcium and magnesium, vitamins A, B2 and B12, not to mention being a complete protein. On the other hand, cheese is also a significant source of saturated fat and sodium in our diets. To lower saturated fat intake, consuming reduced-fat cheese is sometimes recommended to lower cardiovascular disease risk.
U.S. Navy pilots and sailors won’t be considered crazy for reporting unidentified flying objects, under new rules meant to encourage them to keep track of what they see. Yet just a few years ago, the Pentagon reportedly shut down another official program that investigated UFO sightings. What has changed? Is the U.S. military finally coming around to the idea that alien spacecraft are visiting our planet?
For about a century now, scientists have theorized that the metals in our Universe are the result of stellar nucleosynthesis. This theory states that after the first stars formed, heat and pressure in their interiors led to the creation of heavier elements like silicon and iron. These elements not only enriched future generations of stars (“metallicity”), but also provided the material from which the planets formed.
The constellation of Orion (The Hunter) is one of the most recognisable collections of stars in the night sky. We have noted Orion’s prominent stars for tens of thousands of years at least, and likely far longer. Chinese astronomers called it 参宿 or Shēn, literally “three stars”, for its three bright dots (which form the Hunter’s belt). The ancient Egyptians regarded it as the gods Sah and Sopdet, manifestations of Osiris and Isis, respectively, whereas Greek astronomers saw a brave hunter — the eponymous Orion — with his sword above his head, ready to strike.
The news is grim: According to a report compiled by hundreds of scientists from 50 countries, Earth is losing species faster than at any other time in human history. Thanks to climate change, coastal development and the impacts of activities such as logging, farming and fishing, roughly 1 million plants and animals are facing extinction.
In 1924, French physicist Louis de Broglie proposed that photons – the subatomic particle that constitutes light – behave as both a particle and a wave. Known as “particle-wave duality”, this property has been tested and shown to apply with other subatomic particles (electrons and neutrons) as well as larger, more complex molecules.
Managing pilotless aircraft and solar panels that could help humans live on the Moon and Mars are among the technologies NASA is looking to develop with small business awards totaling $106 million. In all, NASA has selected 142 proposals from 129 U.S. small businesses from 28 states and the District of Columbia to receive Phase II contracts as part the agency's Small Business Innovation Research (SBIR) program.
The Moon is shrinking as its interior cools, getting more than about 150 feet (50 meters) skinnier over the last several hundred million years. Just as a grape wrinkles as it shrinks down to a raisin, the Moon gets wrinkles as it shrinks. Unlike the flexible skin on a grape, the Moon’s surface crust is brittle, so it breaks as the Moon shrinks, forming “thrust faults” where one section of crust is pushed up over a neighboring part.
Astronaut Mike Massimino floated next to the Hubble Space Telescope’s cylindrical body and began to remove the screws that fastened a handrail to one of the telescope’s instrument panels. The first three screws came out easily, but when he put his power tool to the final screw, the bit began to spin.